The present disclosure relates to a semiconductor manufacturing process, and particularly to a method of forming a gate dielectric through a multi-plasma nitridation process in combination with silicon oxide deposition by atomic layer deposition.
Gate oxide reliability is one of major reliability issues that advanced semiconductor manufacturing technology faces. The gate oxide of a field effect transistor needs to be as thin as possible while avoiding dielectric breakdown caused by leakage currents. An equivalent gate oxide thickness calculated by capacitance measurements tracks with an equivalent gate oxide thickness calculated by measurements on leakage currents, with the offset being substantially independent of most processing parameters employed to form the gate dielectric. A method of reducing the equivalent gate oxide thickness calculated by measurements on leakage currents without reducing the equivalent gate oxide thickness calculated by capacitance measurements is desired.